From 495a5e94baadefa6ed50390e6655021c127ea266 Mon Sep 17 00:00:00 2001
From: Reid Kleckner <rnk@google.com>
Date: Thu, 24 Sep 2020 16:47:15 -0700
Subject: [PATCH] Revert "[NFCI][IR] ConstantRangeTest: add basic scaffolding
 for next-gen precision/correctness testing"

This reverts commit 9bcf7b1c7a139a455400df109d81c638b9e75150.

Breaks build with MSVC.
---
 llvm/unittests/IR/ConstantRangeTest.cpp | 90 +--------------------------------
 1 file changed, 2 insertions(+), 88 deletions(-)

diff --git a/llvm/unittests/IR/ConstantRangeTest.cpp b/llvm/unittests/IR/ConstantRangeTest.cpp
index 6e574dc..5e8a98e 100644
--- a/llvm/unittests/IR/ConstantRangeTest.cpp
+++ b/llvm/unittests/IR/ConstantRangeTest.cpp
@@ -59,12 +59,6 @@ static void ForeachNumInConstantRange(const ConstantRange &CR, Fn TestFn) {
   }
 }
 
-unsigned GetNumValuesInConstantRange(const ConstantRange &CR) {
-  unsigned NumValues = 0;
-  ForeachNumInConstantRange(CR, [&NumValues](const APInt &) { ++NumValues; });
-  return NumValues;
-}
-
 struct OpRangeGathererBase {
   void account(const APInt &N);
   ConstantRange getRange();
@@ -113,79 +107,6 @@ struct SignedOpRangeGatherer : public OpRangeGathererBase {
   }
 };
 
-struct AccumulatedPrecisionData {
-  unsigned NumActualValues;
-  unsigned NumValuesInActualCR;
-  unsigned NumValuesInExactCR;
-
-  // If NumValuesInActualCR and NumValuesInExactCR are identical, and are not
-  // equal to the NumActualValues, then the implementation is
-  // overly conservatively correct, i.e. imprecise.
-
-  void reset() {
-    NumActualValues = 0;
-    NumValuesInActualCR = 0;
-    NumValuesInExactCR = 0;
-  }
-};
-
-template <typename OpRangeGathererTy, typename Fn1, typename Fn2>
-static void TestUnaryOpExhaustive(Fn1 RangeFn, Fn2 IntFn,
-                                  AccumulatedPrecisionData &Total) {
-  Total.reset();
-
-  constexpr unsigned Bits = 4;
-
-  EnumerateConstantRanges(Bits, [&](const ConstantRange &CR) {
-    // We'll want to record each true new value, for precision testing.
-    SmallDenseSet<APInt, 1 << Bits> ExactValues;
-
-    // What constant range does ConstantRange method return?
-    ConstantRange ActualCR = RangeFn(CR);
-
-    // We'll want to sanity-check the ActualCR, so this will build our own CR.
-    OpRangeGathererTy ExactR(CR.getBitWidth());
-
-    // Let's iterate for each value in the original constant range.
-    ForeachNumInConstantRange(CR, [&](const APInt &N) {
-      // For this singular value, what is the true new value?
-      const APInt NewN = IntFn(N);
-
-      // Constant range provided by ConstantRange method must be conservatively
-      // correct, it must contain the true new value.
-      EXPECT_TRUE(ActualCR.contains(NewN));
-
-      // Record this true new value in our own constant range.
-      ExactR.account(NewN);
-
-      // And record the new true value itself.
-      ExactValues.insert(NewN);
-    });
-
-    // So, what range did we grok by exhaustively looking over each value?
-    ConstantRange ExactCR = ExactR.getRange();
-
-    // So, how many new values are there actually, and as per the ranges?
-    unsigned NumActualValues = ExactValues.size();
-    unsigned NumValuesInExactCR = GetNumValuesInConstantRange(ExactCR);
-    unsigned NumValuesInActualCR = GetNumValuesInConstantRange(ActualCR);
-
-    // Ranges should contain at least as much values as there actually was,
-    // but it is possible they will contain extras.
-    EXPECT_GE(NumValuesInExactCR, NumActualValues);
-    EXPECT_GE(NumValuesInActualCR, NumActualValues);
-
-    // We expect that OpRangeGathererTy produces the exactly identical range
-    // to what the ConstantRange method does.
-    EXPECT_EQ(ExactR.getRange(), ActualCR);
-
-    // For precision testing, accumulate the overall numbers.
-    Total.NumActualValues += NumActualValues;
-    Total.NumValuesInActualCR += NumValuesInActualCR;
-    Total.NumValuesInExactCR += NumValuesInExactCR;
-  });
-}
-
 template <typename Fn1, typename Fn2>
 static void TestUnsignedUnaryOpExhaustive(Fn1 RangeFn, Fn2 IntFn,
                                           bool SkipSignedIntMin = false) {
@@ -2479,16 +2400,9 @@ TEST_F(ConstantRangeTest, binaryXor) {
 }
 
 TEST_F(ConstantRangeTest, binaryNot) {
-  AccumulatedPrecisionData Precision;
-
-  TestUnaryOpExhaustive<UnsignedOpRangeGatherer>(
+  TestUnsignedUnaryOpExhaustive(
       [](const ConstantRange &CR) { return CR.binaryNot(); },
-      [](const APInt &N) { return ~N; }, Precision);
-  // FIXME: the implementation is not precise.
-  EXPECT_EQ(Precision.NumActualValues, 1936u);
-  EXPECT_EQ(Precision.NumValuesInActualCR, 2496u);
-  EXPECT_EQ(Precision.NumValuesInExactCR, 2496u);
-
+      [](const APInt &N) { return ~N; });
   TestUnsignedUnaryOpExhaustive(
       [](const ConstantRange &CR) {
         return CR.binaryXor(
-- 
1.8.3.1